1. Field of the Invention
The present invention relates to a jack system capable of horizontal expansion, vertical expansion, cross-member adjustment, and vertical stacking.
2. Background of the Prior Art
The use of jack systems is almost universal in most construction sites. The jacks permit workers to perform tasks at various heights along the construction job with relative safety. The art is replete with various types of jacks having a variety of features and designs.
There are some desirable features associated with jack systems that have not been adequately addressed by the prior art systems. Specifically, workers may want to vary the width of a jack system in order to accommodate more works, more supplies, or a large piece of machinery to perform the job at hand. While a second jack may be placed behind the first jack in order to expand the width of the jack work site, this solution has drawbacks in that system stability is lessened especially in high elevation jacks. Furthermore, the use of two separate jacks is required.
Another desirable feature that is not adequately addressed by the prior art is the stackability of jack systems. Although jack systems are regularly stacked, the stacking mechanism is usually cumbersome and time-consuming to utilize.
A final feature not addressed by the prior art is the need to vary the relative height of the cross-members. For example, a brick mason may continually want to increase the height of the cross-members upon which he has placed a plank which holds his bricks as he continues to raise the level at which he is placing the bricks onto the building. This allows the brick mason to gain and cleaner access to his supplies and materials.
Therefore, there is a need in the art for a jack system that is capable of expanding along its width and that is easily stackable. Furthermore, the jack must have variable height cross-members. Ideally, such a jack system will be easy to use and be of relatively straightforward design and construction.